Active matrix substrate, liquid crystal panel, liquid crystal display device, liquid crystal display unit, television receiver

• US 8,471,972 B2
• Filed: 07/09/2009
• Issued: 06/25/2013
• Est. Priority Date: 08/18/2008
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Tsubata, Toshihide
• Primary Examiner(s): KIM, RICHARD H
• Application Number:
  US13/055,453
• Publication Number:
  US 20110128455A1
• Time in Patent Office: 1,447 Days
• Field of Search: 349/48
• US Class Current: 349/39
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/13624 having more than one switching element per pixel
• CPC Class Codes: G02F 2203/30 Gray scale

Abstract

An active matrix substrate includes a data signal line (15x), a storage capacity wiring (18x), scan signal lines (16a, 16b), a transistor (12a) connected to the data signal line (15x) and the scan signal line (16a), a transistor (12b) connected to the storage capacity wiring (18x) and the scan signal line (16b), and pixel electrodes (17 a, 17b) formed in a pixel (101) area. The pixel electrode (17a) is connected to the data signal line (15x) through the transistor (12a), and the pixel electrode (17b) is connected to the pixel electrode (17a) through a capacitor (C101) and connected to the storage capacity wiring (18x) through the transistor (12b).

Claims

1. An active matrix substrate comprising:

a data signal line;

a storage capacitance wiring;

a first scan signal line and a second scan signal line;

a first transistor connected to the data signal line and to the first scan signal line;

a second transistor connected to the storage capacitance wiring and to the second scan signal line; and

first and second pixel electrodes formed in a pixel area, the first pixel electrode being connected to the data signal line via the first transistor, the second pixel electrode being connected to the first pixel electrode via a capacitance, the second pixel electrode being connected to the storage capacitance wiring via the second transistor.

2. The active matrix substrate according to claim 1, further comprising:

a third pixel electrode formed in the pixel area, the third pixel electrode being electrically connected to the first pixel electrode.

3. The active matrix substrate according to claim 2, further comprising:

a third transistor connected to the second scan signal line,

wherein the third pixel electrode is further connected to the storage capacitance wiring via the third transistor.

4. The active matrix substrate according to claim 3, comprising:

a coupling capacitance electrode overlapping the second pixel electrode via an interlayer insulating film,

wherein a first lead-out wiring led out from a conductive electrode of the first transistor, a fourth lead-out wiring led out from a conductive electrode of the third transistor, and the coupling capacitance electrode are connected to each other in a same layer, the first lead-out wiring and the first pixel electrode are connected via a contact hole, and the fourth lead-out wiring and the third pixel electrode are connected via a contact hole,

wherein a second lead-out wiring led out from one conductive electrode of the second transistor is connected to the storage capacitance wiring via a contact hole, and

wherein a third lead-out wiring led out from the other conductive electrode of the second transistor is connected to the second pixel electrode via a contact hole.

5. The active matrix substrate according to claim 2, wherein the pixel area is divided into two sections by the storage capacitance wiring crossing the pixel area, the first pixel electrode is arranged at one of the two sections while the third pixel electrode is arranged at the other thereof, and the second pixel electrode is arranged between the first pixel electrode and the third pixel electrode.

6. The active matrix substrate according to claim 2, wherein the first pixel electrode, the second pixel electrode, and the third pixel electrode are arranged such that at least a portion of the first pixel electrode lies adjacent to the first scan signal line, such that at least a portion of the third pixel electrode lies adjacent to the second scan signal line, and such that one edge of the second pixel electrode lies adjacent to the first scan signal line while the other edge thereof lies adjacent to the second scan signal line.

7. The active matrix substrate according to claim 2, further comprising:

a coupling capacitance electrode overlapping the second pixel electrode via an interlayer insulating film,

wherein a first lead-out wiring led out from a conductive electrode of the first transistor and the coupling capacitance electrode are connected to each other in a same layer, and the first lead-out wiring and the first pixel electrode are connected via a contact hole,

wherein a second lead-out wiring led out from one conductive electrode of the second transistor is connected to the storage capacitance wiring via a contact hole,

wherein a third lead-out wiring led out from the other conductive electrode of the second transistor is connected to the second pixel electrode via a contact hole; and

wherein an extended coupling capacitance electrode connected to the coupling capacitance electrode is connected to the third pixel electrode via a contact hole.

8. The active matrix substrate according to claim 2, wherein when applied to a liquid crystal display device, subpixels including the first pixel electrode and the third pixel electrode become bright subpixels, and subpixels including the second pixel electrode become dark subpixels.

9. The active matrix substrate according to claim 1, further comprising:

a third pixel electrode formed in the pixel area, the third pixel electrode being connected to the first pixel electrode via a capacitance, the third pixel electrode being electrically connected to the second pixel electrode.

10. The active matrix substrate according to claim 9, further comprising:

a third transistor connected to the second scan signal line,

wherein the first pixel electrode is further connected to the storage capacitance wiring via the third transistor.

11. The active matrix substrate according to claim 10, comprising:

a coupling capacitance electrode overlapping the second pixel electrode via an interlayer insulating film,

wherein a first lead-out wiring led out from a conductive electrode of the first transistor and the coupling capacitance electrode are connected to each other in a same layer, and the first lead-out wiring and the first pixel electrode are connected via a contact hole,

wherein a second lead-out wiring led out from one conductive electrode of the second transistor is connected to the storage capacitance wiring via a contact hole,

wherein a third lead-out wiring led out from the other conductive electrode of the second transistor is connected to the second pixel electrode via a contact hole, and the third lead-out wiring is connected to the third pixel electrode via a contact hole, and

wherein a fourth lead-out wiring led out from a conductive electrode of the third transistor is connected to the first pixel electrode via a contact hole.

12. The active matrix substrate according to claim 9, wherein the pixel area is divided into two sections by the storage capacitance wiring crossing the pixel area, the second pixel electrode is arranged at one of the two sections while the third pixel electrode is arranged at the other thereof, and the first pixel electrode is arranged between the second pixel electrode and the third pixel electrode.

13. The active matrix substrate according to claim 9, wherein the first pixel electrode, the second pixel electrode, and the third pixel electrode are arranged such that at least a portion of the second pixel electrode lies adjacent to the first scan signal line, such that at least a portion of the third pixel electrode lies adjacent to the second scan signal line, and such that one edge of the first pixel electrode lies adjacent to the first scan signal line while the other edge thereof lies adjacent to the second scan signal line.

14. The active matrix substrate according to claim 9, further comprising:

a coupling capacitance electrode overlapping the second pixel electrode via an interlayer insulating film,

wherein a first lead-out wiring led out from a conductive electrode of the first transistor and the coupling capacitance electrode are connected to each other in a same layer, and the first lead-out wiring and the first pixel electrode are connected via a contact hole,

wherein a second lead-out wiring led out from one conductive electrode of the second transistor is connected to the storage capacitance wiring via a contact hole, and

wherein a third lead-out wiring led out from the other conductive electrode of the second transistor is connected to the second pixel electrode via a contact hole, and the third lead-out wiring is connected to the third pixel electrode via a contact hole.

15. The active matrix substrate according to claim 9, comprising:

a coupling capacitance electrode overlapping the second pixel electrode via an interlayer insulating film,

wherein a first lead-out wiring led out from a conductive electrode of the first transistor and the coupling capacitance electrode are connected to each other in a same layer, and the first lead-out wiring and the first pixel electrode are connected via a contact hole,

wherein a second lead-out wiring led out from one conductive electrode of the second transistor is connected to the storage capacitance wiring via a contact hole,

wherein a third lead-out wiring led out from the other conductive electrode of the second transistor is connected to the second pixel electrode via a contact hole, and

wherein a fourth lead-out wiring led out from a conductive electrode of the third transistor is connected to the first pixel electrode via a contact hole.

16. The active matrix substrate according to claim 9, wherein when applied to a liquid crystal display device, subpixels including the first pixel electrode become bright subpixels, and subpixels including the second pixel electrode and the third pixel electrode become dark subpixels.

17. The active matrix substrate according to claim 16, wherein the storage capacitance wiring includes an extended storage capacitance wiring branching off therefrom, and

wherein when viewed planarly, the extended storage capacitance wiring is provided so as to overlap a portion of an edge of the second pixel electrode and the third pixel electrode or to extend along an outer side thereof.

18. The active matrix substrate according to claim 1, further comprising:

a third transistor connected to the second scan signal line,

wherein the first pixel electrode is further connected to the storage capacitance wiring via the third transistor.

19. The active matrix substrate according to claim 18, wherein the second transistor and the third transistor are formed such that each conductive electrode thereof does not overlap the second scan signal line.

20. The active matrix substrate according to claim 1, wherein the second transistor is formed such that each conductive electrode there of does not overlap the second scan signal line.

21. The active matrix substrate according to claim 1, wherein the storage capacitance wiring forms a storage capacitance with the first pixel electrode.

22. The active matrix substrate according to claim 21, wherein the storage capacitance wiring further forms a storage capacitance with the second pixel electrode.

23. The active matrix substrate according to claim 22, further comprising a storage capacitance electrode formed in a same layer as conductive electrodes of the first transistor and the second transistor, the storage capacitance electrode being electrically connected to the first pixel electrode, the storage capacitance electrode overlapping the storage capacitance wiring via a gate insulating film.

24. The active matrix substrate according to claim 23, wherein at least a portion of a section of the gate insulating film overlapping the storage capacitance electrode is thinned.

25. The active matrix substrate according to claim 24, wherein the gate insulating film is composed of an inorganic insulating film and an organic insulating film, and the organic insulating film is removed from at least a portion of a section of the gate insulating film overlapping the storage capacitance electrode.

26. The active matrix substrate according to claim 22, further comprising a coupling capacitance electrode formed in a same layer as conductive electrodes of the first transistor and the second transistor, the coupling capacitance electrode being electrically connected to the first pixel electrode, the coupling capacitance electrode overlapping the second pixel electrode via an interlayer insulating film, the coupling capacitance electrode overlapping the storage capacitance wiring via a gate insulating film.

27. The active matrix substrate according to claim 26, wherein at least a portion of a section of the interlayer insulating film overlapping the coupling capacitance electrode is thinned.

28. The active matrix substrate according to claim 1, further comprising:

a coupling capacitance electrode overlapping the second pixel electrode via an interlayer insulating film,

wherein a first lead-out wiring led out from a conductive electrode of the first transistor and the coupling capacitance electrode are connected to each other in a same layer, and the first lead-out wiring and the first pixel electrode are connected via a contact hole,

wherein a second lead-out wiring led out from one conductive electrode of the second transistor is connected to the storage capacitance wiring via a contact hole, and

wherein a third lead-out wiring led out from the other conductive electrode of the second transistor is connected to the second pixel electrode via a contact hole.

29. The active matrix substrate according to claim 28, wherein the second lead-out wiring overlaps the second pixel electrode via an interlayer insulating film, and

wherein at least a portion of the interlayer insulating film is thinned.

30. The active matrix substrate according to claim 29, wherein the interlayer insulating film is composed of an inorganic insulating film and an organic insulating film, and the organic insulating film is removed from at least a portion of a section of the interlayer insulating film overlapping the coupling capacitance electrode.

31. The active matrix substrate according to claim 30, wherein the organic insulating film contains at least one of acrylic resin, epoxy resin, polyimide resin, polyurethane resin, novolak resin, and siloxane resin.

32. The active matrix substrate according to claim 1, wherein a storage capacitance is formed between at least one of the first pixel electrode and the second pixel electrode provided in a pixel area of a current row and at least one of the first scan signal line and the second scan signal line for a pixel area of a previous row.

33. The active matrix substrate according to claim 1, wherein when an extension direction of scan signal lines is regarded as a row direction, two scan signal lines correspond to two pixel areas arranged in the row direction, and two pixel electrodes are aligned in the column direction in each of the pixel areas, and

wherein a transistor connected to one of the two pixel electrodes adjacent in the row direction is connected to one of the two scan signal lines, and a transistor connected to the other of the two pixel electrodes is connected to the other of the two scan signal lines.

34. The active matrix substrate according to claim 1, wherein when applied to a liquid crystal display device, subpixels including the first pixel electrode become bright subpixels, and subpixels including the second pixel electrode become dark subpixels.

35. The active matrix substrate according to claim 34, wherein the storage capacitance wiring includes an extended storage capacitance wiring branching off therefrom, and

wherein when viewed planarly, the extended storage capacitance wiring is provided so as to overlap a portion of an edge of the second pixel electrode or to extend along an outer side thereof.

36. The active matrix substrate according to claim 35, wherein the extended storage capacitance wiring is formed by:

a first extension formed in a same layer as the storage capacitance wiring; and

a second extension connected to the first extension via a contact hole and also to an lead-out wiring led out from one conductive electrode of the second transistor.

37. A liquid crystal display device comprising:

the active matrix substrate according to claim 1,

wherein the second scan signal line is selected at least once during display.

38. The liquid crystal display device according to claim 37, wherein a common electrode potential has been supplied to the storage capacitance wiring when the second transistor is turned off.

39. The liquid crystal display device according to claim 38, wherein the first transistor remains on when the second transistor is turned off, or the first transistor is turned off at the same time when the second transistor is turned off.

40. The liquid crystal display device according to claim 37, wherein potentials of the first pixel electrode and the second pixel electrode become substantially a common electrode potential when the second transistor is turned off.

41. The liquid crystal display device according to claim 37, wherein a first gate-on pulse signal supplied to the first scan signal line and a second gate-on pulse signal supplied to the second scan signal line become active during a same horizontal scanning period, and

wherein the second gate-on pulse signal has a pulse width shorter than that of the first gate-on pulse signal, and the second gate-on pulse signal becomes inactive before the first gate-on pulse signal becomes inactive.

42. The liquid crystal display device according to claim 37, wherein a first gate-on pulse signal supplied to the first scan signal line and a second gate-on pulse signal supplied to the second scan signal line become active during a horizontal scanning period immediately prior to a period during which a signal potential of a data signal to be displayed is supplied to the first pixel electrode, and

wherein the second gate-on pulse signal becomes inactive while the first gate-on pulse signal is active.

43. The liquid crystal display device according to claim 37, wherein a second gate-on pulse signal supplied to the second scan signal line becomes active two or more horizontal scanning periods prior to a period during which a signal potential of a data signal to be displayed is supplied to the first pixel electrode, and

wherein the second gate-on pulse signal remains inactive while the first gate-on pulse signal supplied to the first scan signal line is active.

44. The liquid crystal display device according to claim 37, wherein a second gate-on pulse signal supplied to the second scan signal line becomes active two or more horizontal scanning periods prior to a period during which a signal potential of a data signal to be displayed is supplied to the first pixel electrode, and

wherein the second gate-on pulse remains inactive when a first gate-on pulse signal supplied to the first scan signal line becomes active.

45. The liquid crystal display device according to claim 37, wherein a common electrode potential is supplied at least twice in each frame to all pixel electrodes of one pixel area.

46. The liquid crystal display device according to claim 45, wherein the common electrode potential is supplied at least twice in each frame to all pixel electrodes of one pixel area after two-thirds of a frame period has passed after a signal potential of a data signal to be displayed is supplied to the first pixel electrode.

47. The liquid crystal display device according to claim 37, wherein a polarity of a signal potential of a data signal supplied to each data signal line is reversed every horizontal scanning period,

wherein when the polarity of the signal potential of the data signal is reversed, a supply of a data signal to each data signal line is terminated for a predetermined period, and each data signal line is short-circuited to each other, and

wherein the first transistor and the second transistor remain on during the predetermined period.

48. The liquid crystal display device according to claim 37, further comprising:

a scan signal line drive circuit driving each scan signal line,

wherein a first gate-on pulse signal and a second gate-on pulse supplied to the first scan signal line and the second scan signal line, respectively, are generated using an output from a same stage of a single shift register included in the scan signal line drive circuit.

49. The liquid crystal display device according to claim 48, wherein the scan signal line drive circuit comprises the shift register, a plurality of logic circuits arranged in the column direction, and an output circuit, and

wherein pulse widths of the first gate-on pulse signal and the second gate-on pulse signal that are outputted from the output circuit are determined based on an output of the shift register and an output control signal controlling an output of the scan signal line drive circuit, both of which are inputted to the logic circuit.

50. The liquid crystal display device according to claim 37, wherein a polarity of a signal potential supplied to the first pixel electrode is reversed every frame.

51. The liquid crystal display device according to claim 37, wherein a polarity of a signal potential supplied to a first data signal line is reversed every horizontal scanning period.

52. The liquid crystal display device according to claim 37, wherein during a single horizontal scanning period, signal potentials having reversed polarities are supplied, respectively, to a first data signal line and to a data signal line adjacent thereto.

53. A television receiver comprising:

the liquid crystal display device according to claim 37; and

a tuner for receiving television broadcasting.

54. A liquid crystal panel comprising:

the active matrix substrate according to claim 1.

55. A liquid crystal display unit comprising:

the liquid crystal panel according to claim 54; and

a driver.

56. A liquid crystal display device comprising:

the liquid crystal display unit according to claim 55; and

a light source device.